This document discusses solar energy and photovoltaic systems. It begins by providing context on Italy's increased focus on solar energy after the 1973 energy crisis. It then discusses global warming and incentives for renewable energy in Europe. The document provides details on solar energy resources, technologies like solar thermal and photovoltaic panels, and examples of large solar installations. It also discusses strategies to make solar energy more affordable and sustainable, like improving recycling of panels. In conclusion, it notes that the town of San Vendemiano has installed solar panels on local schools to produce clean energy.

1. ISTITUTO COMPRENSIVO SAN VENDEMIANO
– Treviso – Italy –
«G.Saccon»
Lower Secondary School
CLASS 3C
Comenius Project
2012/13

2. Sun vs fossil fuels
In 1973 in Italy, after the energy crisis, we began looking carefully on the
sun as an alternative source for the production of electricity.
In these last years, globalIn these last years, global
warming is changing thewarming is changing the
climatic conditions of ourclimatic conditions of our
planet.planet.
The European Council hasThe European Council has
begun to provide incentivesbegun to provide incentives
for renewable and cleanfor renewable and clean
forms of energy which doforms of energy which do
not involve any kind ofnot involve any kind of
emissions in theemissions in the
atmosphere.atmosphere.

3. Renewable energies: forms of energy produced from renewable sources
that can regenerate at least at the same speed they are used or aren’t “ exhaustible “
in a “human” time scale.Their use doesn’t affect natural resources for the future
generations and are clean energies, not polluting.
Solar energy is the energy associated with
solar radiation and it represents the primary
source of energy on the Earth and it makes
life possible.
The sun irradiates the terrestrial surface with
50 milion GWATT every moment.
Nearly all other other available energy
sources derive from this energy, such as: fossil
fuels, wind, water, biomass, tides.

4. The covered area
needed to provide the
energy equivalent to the
current primary energy
demand is indicated by
the dark disks.
SOLAR ENERGY GLOBAL RESOURCES
The colours on the map show the average solar power that reaches the Earth, also
taking into account cloudiness indicated by weather satellites.
TW (tera watt ) = 1012
W
Twe (tera watt energy)
The scale is in WATT
per square metre.

5. Annual
irradiation in
Italy

6. Advantages
 It is renewable.
 It is a free, clean and unlimited source.
 It does not produce pollution because it
does not burn materials which release
toxic gases in the atmosphere.
 It reduces the consumption of fossil fuels.
 It increases the economic value of a
house.
 It sets in motion an economic sector which
is doing well (Green Economy).
 its systems are strong (25 years
warranty).
 It has low maintenance costs.
 It has a system of modular installation.
• Harmful disposal.
• Discontinuous production.
• Not very high efficiency.
• High surfaces occupied.
• High initial costs.
Disadvantages
Energy from
the sun

7. Solar energy use
Solar energy can be used in many ways, the most used are solar cells and solar
panels.
Solar thermal panels can be:
- for domestic use to produce hot water in small home plants.
- for industrial use to produce steam to generate electricity.
Photovoltaic panels are used:
For domestic and industrial use to produce electricity directly.
Domestic use

9. Natural circulation
thermal solar panels
Natural circulation thermal solar systems are so called
because they exploit hot liquids properties to rise in a
natural way.
(A) Sunbeams heat transfer fluid (water + antifreeze) which
rises naturally up to the tank placed horizontally above
the panels.
(B) The liquid transfers its heat to the water inside the tank
and enters the hydraulic water circuit of the house
1) Valve
2) Storage tank
3) Insertion pipe
4) Absorption panels
5) Cold water insertion pipe.
Diagram of a solar panel

10. Augusto Righi was an Italian
physicist of Bologna and he
was the first to recognize this
phenomenon in 1888
even if you had to wait the writings
of Einstein for a formalization of the
physical principle.
The photovoltaic principleThe photovoltaic principle

11. Photovoltaic Technology
Using semiconductors, solar PV modules create
power by converting sunlight into electricity.
The semiconductor material most commonly used
for the construction of photovoltaic cells is silicon.
The silicon is found in nature
Surely the material most often used is crystalline
silicon, one of the most common chemical elements
in the earth crust.
Other materials used for the construction of
photovoltaic cells are: copper, indium, diselenide,
cadmium, telluride
To coat and protect the thin layers of semiconductor
material, most of the photovoltaic technologies use
glass.
Approximately 80% of the weight of a module is
made of glass.

12. Every cell consists of two main layers: one charged positively
and the other negatively.
A photovoltaic panel is made of some tens of
silicon cells connected by conductor joints
This produces a steady electromagnetic field within the cell
which conveys the flux of electrons.
The aluminum and silicon dioxide layers constitute the
elements of the circuit itself, allowing the current transition.
A photon which interacts with the atoms of the positive layer
arrives (the anti-reflecting layer favours the input) freeing an
electron that is conveyed to the circuit:
WE HAVE THE CURRENT.
The photovoltaic principleThe photovoltaic principle
The capability of photons to extract electrons from atomsThe capability of photons to extract electrons from atoms
is calledis called photoelectric effect.photoelectric effect.
E

13. The most common version of a
photovoltaic cell is constituted
by a lamina of semiconductor
material, the most widespread
of which is silicon, and it is
generally blue or black.
Small amounts of silicon
photovoltaic cells are found in
calculators, watches etc..
The photovoltaic cell efficiency
is obtained by evaluating the
ratio between the electrical
power produced by the cell and
the energy of the solar
radiation that invests the entire
surface .
PHOTOVOLTAIC CELL

14. SOLAR POWER
INSTALLATION
When photons (particles of
Sun energy) strike a
photovoltaic cell, a part of
energy is absorbed by the
material and some electrons
flow through the
semiconductor material
(suitably treated) producing
direct current
fotone Elements of a
photovoltaic plant:
CELLA
MODULO
PANNELLO
STRINGA
CAMPO
CELL
MODULE
PANELS
FIELD
STRINGS

15. SOLAR TRACKING PHOTOVOLTAIC PLANT
Solar tracking is a technology able to increase considerably the production of
electric power from photovoltaic panels.
Efficiency can increase by 45%
The tracking of the sun can be made with a single axle (in this case rotation
takes plase only on the horizontal, or vertical, axle) or with a double axle,
that is rotation takes place both horizontally and vertically at the same time.
In this second way the panels are always head-on the Sun.

16. The process to extract and work silicon is very expensive.
We need to limit the costs of production and sales and develop new technologies
in the future
Strategies for the future:
Expand silicon.
Researchers at Stanford University ,in California, have developed a silicon-based chip which can be
mechanically expanded ("stretchare" in U.S. slang, means stretching the chip in every direction) in order
to cover a wider area. This chip can be up to hundreds of times the original size.
Use nanotechnologies.
“Nanosolar “produces third generation photovoltaic cells obtained by pressing nanoparticles made of
copper, indium, gallium and selenium alloy on flexible material (CIGS: their efficiency is quite the same
to the one of silicon, but their cost is approximately about a fifth, which is lower even than the
exploitation of coal) with a new "ink energy" able to transform solar radiation into electrical energy .
Concentrate sunlight (CPV tecnhology).
“Emcore Corp”, from Canada, a provider of solar stations and space communications systems, has
launched the application of advanced technologies on the Earth. These were tested only out of the
atmosphere before. In this type of cells the concentrator has the size of 1 square centimeter, able to
generate the same energy of 500 square cm of conventional solar cells. The materials used for the
construction of the concentrator are cheap.

17. Most of a solar module components
can be reused.
Thanks to technological innovations
occurred in recent years , up to 95 % of
some semiconductor materials or glass,
as well as vast quantities of ferrous and
non-ferrous metals used in photovoltaic
modules can be recycled.
However, the percentage of photovoltaic
material which is unused or disposed in
landfills not suitable for this purpose is still
very high.
Furthermore, during the disposal process,
with the only exception of certain
materials which do not contain toxic
substances in their composition, heavily
polluting substances from the constituent
materials are released into the
atmosphere.
Recycling panels
THE MAIN OBJECTIVE OF PV
CYCLE is to recycle 80% (in
weight) of a solar module by
2015 and 85% by 2020
From 1° July 2012 photovoltaic
panels producers must have the
membership certificate of an
authority that ensures the recycling
of photovoltaic modules.
In the absence of such membership,
proved by its certificate to be
presented at the time of sale, the
manufacturer cannot allow his
customers to take advantage
of state incentives

18. The largest active installation is
located in California, near Los
Angeles.
It has 118 large panels that exploit
the desert sun producing 250 MW
power.
This solar power installation is going
to reach its maximum power in 2014.
It will increase by 50% the total flow
of solar power plants installated in
the U.S.A. using the “linear parabolic
mirror” concentration technology.
It will be able to cover the
consumpition of 54,000 homes.
Concentration Photovoltaic Installations in
California
The mirrors are concave and at least
10 metres long.
The Sun radiation which reaches them is
concentred on a pipe put on their focus.

19. A photovoltaic installation in
Cremona: in 2011 it produced
5789,257 kwh electricity for
the National Electric system,
net of its own use.
In Europe, the main
photovoltaic power installation
is located near Gargano in the
south of Italy and extends
over an area of 4000 square
meters.

20. It is made of one or more satellites which
convert sunlight into electricity through
photovoltaic cells.
Then they transmit the energy thus obtained
in the form of microwaves or laser through
an antenna.
The advantage consists in the constancy of
lighting and in the lack of weather conditions
(clouds, rain, etc.) which can reduce the flow
of energy.
An orbital solar power station is a hypothetical electric power plant

21. An orbital solar power station is
made of three parts:
• a big solar energy collector with
photovoltaic cells.
• an aerial to transmit microwawes
towards the earth.
• a high dimension aerial on the
Earth that receives microwawes
and changes them into electric
energy.
With a solar power station in space
we would receive direct, constant
lighting with 99% efficiency.

22. A big problem will be sending
materials into orbit. Taking into
account the current cost of space
shuttle, the transport is beetwen
8.000 and 11.000 U.S. dollars per kg.
The exact price will dipend on the
number of launches necessary to send
materials into orbit.
This way to acquire
energy is just at the
experimental stage
at present.
For the future,
scientists are looking
for new systems to
transmit lasers to
the Earth, able to
overcome technical
and economical
obstacles.

23. The most
sustainable city..
In 2010 the Economist Intelligence Unit (EIU) designated
Copenhagen as the most ecologically sustainable European
city.
The British Unit has measured the commitment of 30 cities
in 30 countries in riducing the environmental impact,
analyzing 7 sustainability aspects:
• level of carbon dioxide emissions
• energy consumed
•sustainability of buildings
•system of transport
•use of water
•disposal of rubbish
•use of territory

24. The aim is to improve cities with
sustainable technologies that enable:
• An intelligent managment of car
traffic;
• The development of Smart grids
(they conduct the electric system)
which can develop the use of
renewable energies;
• The development of Smart buildings
(with reduction of energy and
emission of CO2);
SMART CITY: re-think
today’s towns
Technologies have a more and more important role in our
cities and will become an element of daily and spontaneous
use for citizens.
From now to 2020 Italian cities that want to become “Smart” will get state incentives.
A percentage of these incentives is intended for young people aged under 30 who want
to present social innovation projects.

26. Low2No has been developing and
growing for three years: a 100%
sustainable area (zero impact) built
near Helsinki.
Finland is, despite the small number
of its inhabitants, slightly more than
5 million, the third nation in the
world for Co2 emissions. It is
surpassed only by the United States
of America and United Arab
Emirates.
A company from Turin won the call
for bids in September 2009. It will
exclusively use solutions made in
Italy.
Low2No is a project which involves several
economic sectors with "smart services”.

27. The amount of CO2 produced during
daily activities by a family has been
kept under control like a diet.
The Webster family,who lives in Espoo
(Finland) was the protagonist of an
experiment lasted one year and
documented in the film "Recipes for
disaster"
(http://www.youtube.com/watch?
feature=player_embedded&v=qlm6Gvx
dlRE)
The documentary showed how it is possible to adopt a low-footprint lifestyle
without giving up our habits and nice things life can offer.
Giving up plastic products or cars is undoubtedly a difficult choice to be taken, but
absolutely possible, especially if adopted by a group of people.
We can see how two children are able to cope with the new plastic-free life with
energy and enthusiasm.
Low2No wants to promote a more sustainable lifestyle.

28. The choice to adopt
the metaphor of
"Detox Diet"
worked.
John Webster and
his family, after a
year characterized
by challenges,
difficulties, doubts
but also
satisfactions and
small everyday joys,
can effectively
reduce drastically
the “home
production” of Co2.

29. Primary and secondary school
of
San Vendemiano

30. THEY HAVE BEEN INSTALLED
LAYING ON A TERRACE:
one plant
on S. Francesco
PRIMARY SCHOOL
LAYING RETROFIT:
two plants
One on G. Saccon
LOWER SECONDARY SCHOOL
One on S. Francesco
PRIMARY SCHOOL
Photovoltaic Plants
THE TOWN OF S.VENDEMIANO HAS INSTALLED
PHOTOVOLTAIC PANELS WITH POWER UP TO 20Kwp
ON OUR SCHOOLS

31. PRIMARY SCHOOL
laying on a terrace

32. LOWER SECONDARY
SCHOOL
THE PANELS CAN ONLY BE GLIMPSED FROM BELOW
“Retrofit” laying on the roof

33. PHOTOVOLTAIC PLANT DIAGRAM
PHOTOVOLTAIC MODULES INVERTER METER
USERS
EXCHANGE/SALE METERS
NATIONAL
ELECTRIC SYSTEM
DISTRIBUTION
ELECTRIC LINE
DIRECTIN OF ENERGY FLOW FROM THE
ELECTRIC SYSTEM
DIRECTION OF PHOTOVOLTAIC
ENERGY FLOW
it turns the direct current
delivered by the sisystem
into alternate current to
put it in the electric
system

34. KWH of ENERGY
PRODUCED AT
THE MOMENT
KWH of ENERGY
PRODUCED UNTIL
THAT TIME
CO2 NOT PRODUCED AND
NOT RELEASED IN THE
ATMOSPHERE
GRID_CONNECTED: connection to the
national electric system. The energy
produced is transferred into the national
electric system and calculated by the
operator. This one can purchase the energy
produced or allow us to use it when
necessary. In this case, there are state
incentives which allow us to amortize the
cost of the plant.
INDICATOR DISPLAY INSTALLED IN THE HALLS OF SCHOOLS

35. Class 3C
Students
 BAGHIU DIANA
 BARRO DANIELE
 BASEI NICOLE
 BOLDRIN ELENA
 BONETTO PATRICK
 BOLZAN ALESSANDRO
 CASAGRANDE MARCO
 CARIA IVAN
 DAL PONTE ELISABETTA
 DA RIN FIORETTO STEFANO
 DE ZAN TOBIA
 ESPOSITO SAMUELE
 FLAVIANI DEBORA
 GIACOMIN GIOIA
 HU ANGELO
 ISEPPI ANASTASIA
 TRENTIN OSCAR
 SCUDELLER GIOIA
 ZORZINI LORENZO
Teachers:
Silvana Sorce
Gabriella De Pizzol